Unigine::DatasetSpatialReference Class

The DatasetSpatialReference class represents an OpenGIS Spatial Reference System (SRS). The class uses GDAL API to retrieve data from strings in WKT (Well-known text) format.

DatasetSpatialReference Class

Members

---

DatasetSpatialReference(const char * wkt_string = 0)

Constructor. Takes a string argument which should be a WKT representation of an SRS.

Arguments

• const char * wkt_string - Well known text definition to which the object should be initialized.

int isOwner()

Returns the owner flag. If the pointer is the owner, on its deletion the DatasetSpatialReference also will be deleted. Use grab() and release() functions to change ownership.

Return value

Owner flag.

void grab()

Grabs the DatasetSpatialReference (sets the owner flag to 1). The DatasetSpatialReference should not be handled by the engine after this function is called.

int importFromWkt(const char * wkt_string)

Imports the SRS definition from WKT string, wipes the existing one and reassigns it based on the contents of the passed WKT string.

Arguments

• const char * wkt_string - WKT string.

Return value

0 if import succeeds; otherwise, 1.

int setWellKnownGeogCS(const char * str)

Sets a GeogCS based on well known name.

Arguments

• const char * str - Name of well known geographic coordinate system.

  The following well known text values are supported:

  • WGS84 - same as EPSG:4326 but has no dependence on EPSG data files.
  • WGS72 - same as EPSG:4322 but has no dependence on EPSG data files.
  • NAD27 - same as EPSG:4267 but has no dependence on EPSG data files.
  • NAD83 - same as EPSG:4269 but has no dependence on EPSG data files.
  • EPSG:n - n is a GCS or PCS code from the horizontal coordinate system table.

Return value

0 on success; otherwise, 1.

void release()

Releases the dataset (sets the owner flag to 0). The dataset should be handled by the engine after this function is called.

int isValid()

Returns a value indicating if the instance contains valid reference system.

Return value

1 if the instance contains valid SRS; otherwise, 0.